Ultrasound imaging is becoming more and more widely used in clinical care due to its non-invasive, no radiation, portable and low-cost characteristics compared to other imaging modalities such as CT, MR, and PET. Together with its fast growing usage, more and more clinical staffs are getting access to ultrasound imaging systems. This brings a big challenge to the health care system since ultrasound imaging system is one of the most complicated medical imaging systems to use due to the tissue dependence of the ultrasound wave propagations.
As a mechanical wave, ultrasound wave propagation is affected by a number of facts such as the tissue scattering and absorption, variations in propagation speed and dispersion in tissue. As a result, ultrasound imaging in human tissue suffers from loss and defocusing of the propagating energy which varies substantially from patient to patient. Thus, many controls are needed to allow customers to adjust the transmit and receive paths when imaging different patients. Typical ultrasound imaging systems usually have a big control console with many control buttons. Given the need to adjust a number of imaging controls through the console, each patient's ultrasound scan can take 20 to 40 minutes even for experienced clinicians. The required exam time can be even longer for a clinician who is not familiar with the ultrasound controls. This severely affects the clinical efficiency and slows down the clinical work flow, thus affecting the profitability of the health care system. Further, it takes about 1-2 years for a fresh clinical student to be trained to operate an ultrasound imaging system to get the proper images needed for diagnosis. This is a burden that most of the new ultrasound customers cannot afford. On the contrary, the other imaging modalities, such as CT and MR, are much easier to use. Their image quality is not affected by tissue properties, thus, eliminating the need for complicated imaging control adjustments. Given these problems, there is a need to have an ultrasound imaging system that is as simple to operate as a CT or MR system, with little or no user involvement in the imaging process.
Numerous solutions to the above-described problem have been proposed. For example, many high-end ultrasound systems have imaging presets created in-house based on different patient types. A user can select one of the settings when a patient with an obesity problem is being scanned, or select another setting when a thin patient is being scanned. These pre-set imaging parameters certainly help the image quality and reduce the number of adjustments needed. However, these settings are hard to create in-house due to the lack of the pathologies. In addition, if the patient's pathology differs from the pre-set pathology, which happens frequently, these settings do not perform well. Some prior art devices have tried to use patient information to adjust the settings. For example, a gain adjustment in B mode imaging has been presented by Larry Mo., in U.S. Pat. No. 6,102,859, Method and Apparatus for Automatic Time and/or Lateral Gain Compensation in B-mode Ultrasound Imaging. This patent describes the use of current tissue echo intensity to adjust the system gain distribution. In U.S. Pat. No. 6,508,774, to Acker et al., a HIFU system with feedback control is disclosed, where a feedback signal identifies cavitations and the system then moves the HIFU focus away from the cavitations to avoid further damage. In another example, Hao, et al., in U.S. Patent Application No. 20060173311, Method and System for Controlling an Ultrasound System, introduces feedback control of acoustic power output to reach a certain MI value in micro-bubble contrast imaging. However, how this idea can be extended to general ultrasound imaging remains unknown. So far, there is no smart system that can adjust the imaging parameters automatically to reach the best performance of the system for each particular patient in all aspects.